On Wed, 11 Jan 2012 10:46:27 +0300
Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> On 32 bit systems num_aces * sizeof(struct cifs_ace *) could overflow
> leading to a smaller ppace buffer than we expected.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
> index 72ddf23..c1b2544 100644
> --- a/fs/cifs/cifsacl.c
> +++ b/fs/cifs/cifsacl.c
> @@ -909,6 +909,8 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
> umode_t group_mask = S_IRWXG;
> umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
>
> + if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *))
> + return;
> ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
> GFP_KERNEL);
> if (!ppace) {
Looks plausible. This function could use some work. I'm not sure why
num_aces is signed here too...
The first arg to kmalloc is a size_t. Does that boil down to an unsigned
long on all arches?
--
Jeff Layton <jlayton@xxxxxxxxx>
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